The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner. The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

The present invention is drawn to artificial metalloenzymes for use in cyclopropanation reactions, amination and C—H insertion.

Metal-organic frameworks (MOFs) may have Zn(II), Pb(II), and/or Cd(II) as a central metal ion, a 4,4′-bipyridylethylene (bpe) ligand as a first ligand; and fumaric acid (fum) and/or oxalic acid (ox) as a second ligand, wherein the 4,4′-bipyridylethylene ligands are stacked in the MOF, and wherein a distance between two consecutive 4,4′-bipyridylethylene ligands is less than 5 Å. Cycloadditions, particularly photoinduced [2+2] cycloadditions may be catalyzed by such MOFs, and/or the conversion of photoinduced [2+2] cycloadditions in inventive MOFs may be increased by mechanical force, such as by grinding.

Metal-organic frameworks (MOFs) may have Zn(II), Pb(II), and/or Cd(II) as a central metal ion; a 4,4′-bipyridylethylene (bpe) ligand as a first ligand; and fumaric acid (fum) and/or oxalic acid (ox) as a second ligand, wherein the 4,4′-bipyridylethylene ligands are stacked in the MOF, and wherein a distance between two consecutive 4,4′-bipyridylethylene ligands is less than 5 Å. Cycloadditions, particularly photoinduced [2+2] cycloadditions may be catalyzed by such MOFs, and/or the conversion of photoinduced [2+2] cycloadditions in inventive MOFs may be increased by mechanical force, such as by grinding.

The present disclosure discloses a continuous preparation method for a penem intermediate MAP. The continuous preparation method includes the following steps: step S1, in a column-type continuous reactor, using a rhodium-loaded catalyst to catalyze 4-nitrobenzyl(R)-2-diazo-4-((2R,3S)-3-((R)-1-hydroxyethyl)-4-oxoazetidin-2-yl)-3-oxopentanoate to generate a cyclization reaction so as to form a first intermediate, herein the rhodium-loaded catalyst is loaded in the column-type continuous reactor, and the rhodium-loaded catalyst has the following structural formula:

##STR00001##

step S2, performing an esterification reaction on the first intermediate, a diphenyl chlorophosphate and a diisopropylethylamine in a second continuous reactor, to obtain a product system containing the penem intermediate MAP; and step S3, performing crystallization treatment on the product system, to obtain the penem intermediate MAP.

A catalyst and a method for synthesizing cyclic carbonate using the catalyst are provided. The catalyst includes a metal complex shown in formula (I): ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.4, and R.sup.5 are independently a C1-C25 alkyl group, a C1-C25 alkoxy group, a C3-C8 cycloalkyl group, a C6-C25 aryl group, a C6-C25 aryloxy group, a C7-C25 aralkyl group, a C7-C25 aralkoxy group, or halogen; R.sup.3 is hydrogen, a C1-C25 alkyl group, a C3-C8 cycloalkyl group, a C6-C25 aryl group, a C6-C25 aryloxy group, a C7-C25 aralkyl group, or a C7-C25 aralkoxy group; M is Sn or Ti; X is Cl, Br, I, or OAc; and L represents ether or furan.

An aluminum catalyst is obtained by reacting at least one compound of a specific alkylaluminum compound and a specific hydridoaluminum compound with a specific hydroxy compound. The specific hydroxyl compound is a specific 2-cycloalkyl-6-arylphenol or a specific di(2-cycloalkyl-6-arylphenol). A method for producing isopulegol or optically active isopulegol includes selectively cyclizing citronellal using the aluminum catalyst.

A composition, method, and article of manufacture are disclosed. The composition and the article of manufacture include a silica particle and light upconversion molecules incorporated into the silica particle. The method includes obtaining sidechain-modified light upconversion molecules, and incorporating the sidechain-modified light upconversion molecules into a silica particle to form a light upconversion particle.

The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner. The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

Provided herein are methods for converting CBD to a product mixture comprising Δ.sup.8-THC, Δ.sup.9-THC, or a combination thereof. The methods provided herein may comprise one or more of (1) a contacting step wherein a starting material comprising CBD, a carboxylic acid catalyst, and optionally a solvent are added to a reaction vessel, thereby forming a reaction mixture; (2) a conversion step wherein at least a portion of the CBD is converted to THC, thereby forming a product mixture; and (3) optionally, a separation step wherein at least a portion of the carboxylic acid catalyst is removed from the product mixture. In preferred embodiments, the methods utilize a carboxylic acid that is commonly used as a food additive and is generally recognized as safe for human consumption. The methods provided herein do not require the use of catalysts or other reagents that are hazardous to human health.